Nissan A engine
The Nissan A series of internal combustion gasoline engines have been used in Datsun, Nissan and Premier brand vehicles. Displacements of this four-stroke engine family ranged from 1.0-liter to 1.5-liter and have been produced from 1967 to the present. It is a small-displacement four-cylinder straight engine. It uses a lightweight cast iron block and an aluminum cylinder head, with overhead valves actuated by pushrods.
The Nissan A engine design is a refined, quiet and durable gasoline engine. It appears to be a modern replacement of the earlier iron-headed Nissan E engine and is of similar dimensions. The 1960s E series was an all-new design from newly acquired Aichi Kokuki, and integrated Nissan's improvements to the BMC A-Series engine design in the 1950s (Nissan was a licensee of Austin Motor Company technology). As production continued, 1974 and newer A-series engines have different block castings, with relocated motor mount bosses.
A10: the first A-series engine
The A10 is a 1.0-liter (988 cc) engine, released in September 1966 in the 1967 model year Datsun 1000. The A10 featured a three main bearing crankshaft. Bore was 73 mm and stroke was 59 mm (same as the Nissan C engine). With a two-barrel Hitachi carburetor and an 8.5 to 1 compression ratio this engine produced 62 bhp (46 kW) at 6,000 rpm and 61.5 lb·ft. of torque (83 Nm). The Datsun 1000 Coupe, introduced in Sept 1968, was equipped with an uprated A10 engine boasting a free flowing dual outlet exhaust manifold with increased compression, now 9 to 1. With a revised carburetor, this engine produced 66 bhp (49 kW). Later versions of A10 produced 59 hp (SAE). A belt-driven SOHC version of the A10 was built as the E10 into the early nineties.
A12 (1200): further refinements
The A12 is a 1.2-liter (1,171 cc) engine with 73 mm bore, like the previous A10 engine, but the stroke is increased to 70 mm. With five main bearings on a forged steel crankshaft, the engine is extremely smooth and durable. The twin-barrel Hitachi carburettor was significantly improved with the addition of a power valve circuit. It produced 70 hp (51.45 kW) and 70 lb·ft. (94.9 Nm).
A special version of the A12 called the "A12 GX" engine, was available (A12GX or A12T for front-wheel drive applications). With twin Hitachi sidedraft carburetors, a longer duration camshaft and 10:1 compression ratio, the engine accomplished 83 hp (62 kW) @6400 rpm, up 20% from standard A12 engines. The GX engine was offered in Japanese Domestic Market Nissan Sunny 1200 GX sedans and coupes. The identical specification A12T engine was offered in the front-wheel-drive Nissan Cherry X-1. 
An overbored version of the A12 was used in period race cars, including Nissan factory (works) racing Sunnys. Many were bored from the original 73 mm to 76.76 mm using Tomei forged pistons for a displacement of 1,296 cc while others used the Datsun Competition forged pistons of 76 mm to displace 1,270 cc. These legendary engines competed in Japan's Touring Sedan (TS) class races against the 1200s archrival Toyota Starlet. 
The AY12 was used in an under 1,300 cc class with a 76 mm to 76.8 mm piston. The intake valve was 40–41 mm and exhaust valves were 33 mm or 34 mm. The pistons were also a special design and the valve rocker system was different from the standard A12 due to the crossflow layout.
- 1971–1973 Nissan Sunny B110, and B120 (Nissan Sunny Truck)
- 1971–1973 Nissan Cherry E10 (Datsun 120A)
- 1970 Nissan 270X Concept
For the 1974 model year, the A engine was modified, and all subsequent A engines use the new block style. Since there was increasing need for accessories like air conditioning, anti-pollution air pumps and the like, the distributor was moved from the front side of the engine to the middle of the block to make room for these accessories. Additionally, the motor mount positions were moved slightly. Nissan introduced its emission control technology, called NAPS (Nissan NAPS) with the redesign.
This "new" A12 retained the same bore, stroke and most other specifications of the previous A12.
- 1974–1978 Nissan Sunny B210 (Datsun 120Y) (not used in the US model B-210)
- 1974–1976 Nissan Cherry E10 (Datsun 120A)
- 1977.11-1982 Nissan Sunny B310 (Datsun 120Y) (not used in the US model 210)
- 1974–1995 Nissan Sunny Truck
- 1978–1982 Nissan Pulsar N10 / Nissan Cherry N10 (Datsun 120A)
- 1978–1988 Nissan Vanette (C120) – 64 PS (47 kW) at 5,400 rpm (called Datsun Vanette/Nissan Sunny Vanette/Nissan Cherry Vanette, depending on dealership channel)
- Premier 118NE sedan, made by Premier in India
The A12A is a 1.2-liter (1,237 cc) engine. It used a casting similar to the A12 and same stroke, but used a 75 mm bore (up from 73 mm), for an increase of 66 cc capacity. It too was of an overhead valve design. Also used a different(stronger) conrod with a larger diameter gudgeon pin.
The A12A shared a common block and crankshaft with the redesigned A12 and A13 engines.
- 1977.11–1980.11 Datsun Sunny B310 – 70 PS (51 kW) at 6,000 rpm
- 1979–1982 "Datsun 210", USA and Canada version of Sunny B310.
- Datsun Cherry N10
A13 (1974): the first tall-deck A engine
The 1974 A13 is a 1.3-liter (1288 cc) engine with 73 mm bore like the A10 and A12 above, but stroke increased to 77 mm, and compression ratio reduced to 8.5:1.
This engine features a "tall-block" with a deck height 15 mm (0.59 inch) higher than previous A-series engines.
- 1974 Nissan Sunny Datsun B-210 (USA and Canada)
Making this engine a 75 hp (56 kW). An important fact is that this model (B210) just existed in 1974.
A13 (1979–1982) – short-deck engine
The redesigned A13 is a 1.3-liter engine. It used the same basic block casting as the A12 and same stroke of 70 mm, but used a 76 mm bore for a displacement of 1,270 cc. This engine was also used as the base for a number of Formula Pacific and Formula 3 race engines.
- 1980–1982 Nissan Sunny B310
The A14 is a 1.4-liter (1,397 cc) engine produced from the 1975 Model year through current year as of 2008. The bore was increased to 76 mm, up from 73 mm of previous A-series engines. Like the previous A13 engine, the A14 is a "tall-block" variant. It was produced in various ratings from 50 Horsepower to 85 hp (63 kW).
A twin-carburetor "GX" version of this engine (A14T) was available in some markets.
- 1975–1978 Nissan Sunny B210 (140Y or B-210)
- 1977.11-1982 Datsun Sunny HB310 (aka Datsun 140Y or Datsun 210)
- 1977–1982 Nissan Pulsar N10 (aka Datsun/Nissan Cherry, Datsun 310) 92 hp (JDM)
- 1977–1981 Nissan Stanza/Auster/Violet, 80 PS (JDM)
- 2007 Nissan LDV 1400 (model B140). See Nissan Sunny.
- 1978–1988 Nissan Vanette (PC120) – 75 PS (55 kW) at 5,400 rpm (originally only in 'Coach' passenger versions)
- Datsun Forklift models (including turbocharged variant). Replaced the A15 normally aspirated engine due to emission controls implemented in the Asian markets.
A fuel-injected version (A14E) was offered in Asian markets in the B310.
A15 – Stroker motor
The A15 is a 1.5-liter (1,487 cc) engine produced from 1979 through 1998 (and still in production in 2009 for the Malaysian built Vanette C22). The stroke was increased by 5 mm from the A14 engine to now measure 82 mm, while the bore remained 76 mm. It produces 80 hp (60 kW). It used only a different block casting number, but retained the same "tall-block" deck height, measurements and BMEP as the A14. In the Nissan B120 Sunny "RoadStar" truck it is capable of 49 mpg (17,3 km/L).
A fuel-injected version of the A15 (A15E) was offered in Asian markets.
- Nissan Sunny B310 ("Datsun 210")
- Nissan Cherry F10 ("Datsun F10")
- Nissan B120 Pickup ("RoadStar" and "SportStar") in New Zealand
- 1985 – 2009 Nissan Vanette C22
- Datsun 310 N10 in United States
- Nissan forklift: Replaced the commercial J15 engine from 1974 to 1978
- Nissan Sunny Vanette (catalog), Nissan Motor Co, p. 19, 8101D
- Datsun Sunny (catalog), Nissan Motor Co, p. 29, 8053T711
- Costa, André & Georges-Michel Fraichard, ed. (September 1979). "Datsun Cherry". Salon 1979: Toutes les Voitures du Monde (in French). Paris: l'Auto Journal (14 & 15): 176.
- Lösch, Annamaria, ed. (1980). World Cars 1980. Pelham, NY: The Automobile Club of Italy/Herald Books. p. 368. ISBN 0-910714-12-6.
- Datsun RoadStar/SportStar Options, Nissan New Zealand, retrieved 2011-02-13
- SP Workshop Manual Series No. 111: Datsun 120Y, Sunny, B210, ISBN 0-85566-177-1.
- Service Manual Model A10 and A12 Engine, Nissan Motor Co. Ltd, June 1971
- Datsun Sunny B310 Japan Domestic Market parts catalog, Nissan Motor Co. Ltd, October 1983